Simple interest


  1. If a man receives on one-fourth of his capital 3% interest, on two third 5% and on the remainder 11%, the percentage he receives on the whole is









  1. View Hint View Answer Discuss in Forum

    According to question , we have

    Required percent =
    1
    × 3 +
    2
    × 5 + 1 -
    1
    -
    2
    × 11
    4343

    Correct Option: B

    According to question , we have

    Required percent =
    1
    × 3 +
    2
    × 5 + 1 -
    1
    -
    2
    × 11
    4343

    Required percent =
    3
    +
    10
    +
    11
    =
    9 + 40 + 11
    = 5%
    431212


  1. Arun lends ₹ 20,000 to two of his friends. He gives ₹ 12,000 to the first at 8% p.a. simple interest. Arun wants to make a profit of 10% on the whole. The simple interest rate at which he should lend the remaining sum of money to the second friend is









  1. View Hint View Answer Discuss in Forum

    We know that ,

    ∴ SI =
    P × R × T
    100

    According to question ,
    S.I. on 12000 =
    12000 × 8 × 1
    = ₹ 960
    100

    Desired gain on ₹ 20000
    = 20000 × (10 ÷ 100) = ₹ 2000
    ∴ S.I. on ₹ 8000 = 2000 – 960 = ₹ 1040

    Correct Option: D

    We know that ,

    ∴ SI =
    P × R × T
    100

    According to question ,
    S.I. on 12000 =
    12000 × 8 × 1
    = ₹ 960
    100

    Desired gain on ₹ 20000
    = 20000 × (10 ÷ 100) = ₹ 2000
    ∴ S.I. on ₹ 8000 = 2000 – 960 = ₹ 1040
    ∴ Rate =
    SI × 100
    Principal × Time

    Rate =
    1040 × 100
    800

    Rate = 13% per annum



  1. A person lends 40% of his sum of money at 15% per annum, 50% of rest at 10% per annum and the rest at 18% per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum ?









  1. View Hint View Answer Discuss in Forum

    Let the person have ₹ 100.
    Then

    SI for 1 year = ₹
    40 × 15 × 1
    +
    30 × 10 × 1
    +
    30 × 18 × 1
    100 100 100

    Correct Option: C

    Let the person have ₹ 100.
    Then

    SI for 1 year = ₹
    40 × 15 × 1
    +
    30 × 10 × 1
    +
    30 × 18 × 1
    100 100 100

    SI for 1 year = ₹ (6 + 3 + 5.4) = ₹ 14.4
    ∴ Rate of interest on whole sum = 14.4%


  1. The effective annual rate of interest, corresponding to a nominal rate of 6% per annum payable half yearly, is :









  1. View Hint View Answer Discuss in Forum

    Let the sum be ₹ 100.
    For initial six months,

    Simple Interest = 100 ×
    6
    ×
    6
    = 3%
    100 12

    Now, sum = 100 + 3 = ₹ 103
    For another six months,

    Correct Option: D

    Let the sum be ₹ 100.
    For initial six months,

    Simple Interest = 100 ×
    6
    ×
    6
    = 3%
    100 12

    Now, sum = 100 + 3 = ₹ 103
    For another six months,
    Simple Interest = 103 ×
    6
    ×
    6
    = 3.09
    100 12

    ∴ Rate of interest per annum = 3 + 3.09 = 6.09%



  1. A sum of ₹ 1000 is lent out partly at 8% and the remaining at 10% per annum. If the yearly income on the average is 9.2%, the two parts respectively are









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    Let p be lent on 8%.
    ∴ (1000 – p ) is lent on 10%.
    Simple Interest = 9.2% of 1000 = ₹ 92

    SI =
    P × R × T
    100

    ∴ 92 =
    p × 8
    +
    (1000 - p)
    × 10
    100 100

    Correct Option: A

    Let p be lent on 8%.
    ∴ (1000 – p ) is lent on 10%.
    Simple Interest = 9.2% of 1000 = ₹ 92

    SI =
    P × R × T
    100

    ∴ 92 =
    p × 8
    +
    (1000 - p)
    × 10
    100 100

    ⇒ 8p + 10000 – 10p = 9200
    ⇒ – 2p = 9200 – 10000
    ⇒ p = 800 ÷ 2 = ₹ 400 = First part
    ∴ Second part = ₹ 600